delivery dates need to be reset

Hi all,

I came across a scenarion:

Client wants that while creating Sales Order, the delivery date should pick up only the furture date and no past dates or current dates should be picked up. the options in the delivery date should be like this : future date should be enabled

past dates and current dates: disable

i.e if we create a Sales Order on 11.12.2007, then delivery dates should have options of future dates starting from 12.12.2007 only. The options for past dates and current dates like 11.12.2006 and 11.12.2007 should be disable. So, that end users cannot pick accidentally past or current dates.

Thanks in advance,

Sourav